Select Administration > Manage Accounts.
Filter the list of accounts
Enter the Account you want to find (if you know it) in the Filter box.
Use the Filter to shorten the list displayed, by entering a character or characters you think are in the account.
Show out of use accounts
Click Show out of use.
Out of use accounts are shown greyed out in the List of Accounts.
Hide out of use accounts
Click Hide out of use.
Only in use accounts are shown in the List of Accounts.